We present the distribution of 13CO column density of
the first quadrant (l = 8 - 90) of the Galactic Plane
using the 13CO Bell Laboratories Survey and UMass-Stony
Brook 12CO Survey. We estimate the column density
channel by channel (with a velocity step of 1 km/sec) with
LTE assumption, generating the coumn density cube data for
the first quadrant. Spatial resoultion is smoothed into 6
arcminute for whole direction. The highest column density is
estimated to be 9.3x1016 cm-2 per channel, which
is one of the densest part of the Galactic Ring region. Good
correaltionship is found between 13CO integrated
instensity and column density. We discuss some
charateristics of the column density distribution.

This work is supported by Creative Initiative Research Fund
99-NZ-01-01-A-31 of the Ministry of Science and Techonology,
Republic of Korea.

The author(s) of this abstract have provided an email address
for comments about the abstract:
yulee@trao.re.kr